Partnership for the Delaware Estuary collected as-built and final RTK-GPS elevation surveys of the deployed structures. Position of Erosion Control Structures: Nine total RTK-GPS survey points were taken around each structure to monitor elevation change; three along the waterward substrate edge, three along the along the landward substrate edge, and three along the top of each structure spine. Points were collected around and along each structure at deployment (2016-2018) and in 2022, and were used to calculate the average change in vertical position of each breakwater and the immediate surrounding area since deployment.